Field of the Invention
The present invention relates to a new and useful protective envelope for storing a flexible disk cartridge for information processing systems.
Flexible disk cartridges are well known in the art and used extensively in computers and other information processing systems for storage of information signals. The disk itself on which information signals are stored is a circular device which has a magnetic coating on at least one side thereof. The disk is enclosed in a plastic jacket which includes an outer cover and a non-abrasive liner. Accordingly, a disk cartridge is an assembly of the jacket and the disk.
Because of the extensive use of flexible disk cartridges by the computer industry it was necessary that the general, physical and magnetic characteristics of the disk cartridge be standardized to allow interchangeability. Such standardization is evidenced by the regulations promulgated by the American National Standards Institute, Inc. (ANSI), such as those set forth in an ANSI X3.82-1980 report which relates to a 5.25 inch flexible disk cartridge.
It is very important that the flexible disk cartridges be treated with care to prevent inadvertent damage to the disk or non-reproducibility of the information stored thereon. These flexible disks are susceptible to extreme temperature conditions, exposure to magnetic fields or static electricity, dust and dirt and are sensitive to pressure caused by, for example, a writing instrument. Exposure to such conditions may adversely affect the operation of the disk cartridge and the reproducibility of the stored information. For these reasons, the industry found it advantageous to store such disk cartridges in protective envelopes.
The protective envelopes currently on the market comprise basically a rear wall and a front wall joined together at the bottom and two opposite sides to form an open pocket, which is dimensioned to receive the disk cartridge. The height of the rear wall may be greater than that of the front wall so that it extends beyond the opening of the pocket. Such a design allows the cartridge to be easily inserted into and removed from the protective envelope. The depth of the pocket formed by joining the rear and front walls of the protective envelope is usually about 2/3 to 3/4 the diameter of the disk.
There are many inherent problems with this open pocket protective envelope design. The protective envelope described above allows a portion of the disk jacket to be exposed, including the important "write-enable" notch formed on a side edge of the jacket. The disk jacket has several openings formed thereon. A circular opening centrally located exposes the index opening formed in the disk. Another opening formed in the jacket is elongated and extends radially from the center of the jacket. This opening exposes a portion of the disk so that the information stored on the disk may be read by computer peripheral equipment without removing the disk from the jacket. It is possible to inadvertently insert the disk cartridge upside down into the protective envelope thus leaving the elongated opening of the jacket extending beyond the confines of the envelope pocket and exposing a portion of the disk itself to dirt, dust or other adverse conditions. This may result in either damage to the disk or loss of information stored thereon. Even if the cartridge is correctly inserted, the current design of protective envelopes does not prevent potential magnetic film damaging particles from entering the jacket through the exposed write-enable notch or entering the protective envelope pocket.
Furthermore, the jacket itself may be damaged. Because the depth of the pocket is usually less than the height of the jacket, the cartridge projects from the pocket and leaves two corners of the jacket and the write-enable notch exposed. The exposed corners can be easily bent or crinkled causing the disk reader to malfunction or reject the cartridge. In addition, it is a common practice to cover the write-enable notch with a tab to prevent inadvertent erasure or writing over of the information stored on the disk. The write-enable tab may come loose or be pulled off thus voiding the intended purpose of write protecting the data stored on such flexible disk cartridge.
Another inherent problem with the protective envelopes currently known in the art is that the disk may be damaged when the protective envelope is labeled by writing with a sharp instrument, such as a pen or pencil, when the cartridge is in the envelope. Usually the extension of the rear wall does not provide sufficient space for properly labeling the envelope. In such cases it is necessary to write on portions of the front and rear walls which form the pocket. The contact pressure of the writing instrument may be sufficient to cause an impression to be left on the surface of the disk thus damaging the disk or causing the disk to be non-operative when read by a disk reader. In order to protect the disk from being damaged, it would be necessary to remove the cartridge before labeling the envelope. Furthermore, unlike a disk which can be erased and reused many times, protective envelopes cannot be recycled as they are often marked in ink or heavy pencil. The many labeling systems available today compound this problem by offering non-standard and often messy labeling alternatives. In addition, current designs have sacrificed a detailed disk table of contents or index area for necessary promotional or corporate image considerations, leaving only a relatively small area for labeling the envelope.
Furthermore, most of the protective envelopes currently on the market are constructed from very thin and flimsy material. As such they do little to support the disk cartridge and to prevent the cartridge from being inadvertently bent or creased.